1. Field of the Invention
The present invention relates to a method of performing an ion implantation. More particularly, the present invention relates to a method of performing an ion implantation using an ion beam blocking component and an ion beam blocking device having the same to collect particles generated when an ion beam impinges on an ion beam blocking component.
2. Description of Related Art
With the development of semiconductor technology, in a semiconductor manufacturing process, different specific impurities are added into a certain part or a certain film layer, and such a step is called doping and the added impurities are called dopants. Currently, the conventional doping methods can be substantially classified into a diffusion method and an ion implantation method. The diffusion method is usually called a thermal diffusion method since the impurities are self-diffused from a high concentration region to a low concentration region in a host material at high temperature (usually 800° C. or so), thereby achieving the doping purpose. With regard to the ion implantation method, the impurities are dissociated into ions firstly, and after acceleration and selection, specific ions are directly impinged into the host material, so as to achieve the doping purpose.
A common ion implanter mainly includes an ion source, an analyzer, a Faraday flag, an electron shower, and a wafer disk assembly. The ion source is used to provide ions to be implanted, and the ions include different chemical elements and pass through a magnetic field in the analyzer. The analyzer selects some ions to impinge the wafer according to a generated mass to charge ratio of the ions, so as to perform ion implantation. The Faraday flag is a monitor element used to measure and prepare before the implant of ions. The Faraday flag is usually made of graphite. Before the ion implantation, the Faraday flag is used to block an ion stream. On the contrary, when the ions are being implanted, the Faraday flag is moved to allow the ions to impinge on the wafer. When at a closed position, the Faraday flag blocks the ion beam, thereby causing a secondary electron emission. Since the secondary electrons may cause an error in measuring an ion beam current, a magnet is attached on the Faraday flag, so as to prevent the secondary electrons from flowing out. The electron shower is used to neutralize charges of the wafer. The wafer disk assembly is used to fix the wafer and scan the wafer by the use of the ion beam.
U.S. Pat. No. 5,998,798 discloses “ion dosage measurement apparatus for an ion beam implanter and method.” In the ion implanter, a movable restriction plate is attached to one end of the Faraday flag, and a gap exists between the Faraday flag and the restriction plate. The restriction plate is moved relative to the Faraday flag to adjust the quantity of the ion beams passed. However, since the restriction plate is a sheet-like structure, the particles impinged on the restriction plate will contaminate a traveling path of the ion beam and a chamber where the wafer is placed, thus degrading the yield of products.